The pair, who are set to marry later this year, became engaged on New Year's Eve following a hirlwind romance.
The British funnyman dislikes the singer's hectic touring and promotional schedule, but understands he has to cope with periods without his lover.
And the actor insists that despite their busy careers, they are determined to make their relationship work by seeing each other as frequently as possible.
He says, "We are separated a lot but we don't ever go more than two weeks without seeing each other. We've got that little rule sorted. Obviously, it's not ideal, but I've met somebody I've fallen in love with. She's a pop star and it's going to be difficult. I've just got to accept it."